Feasibility and Reproducibility of Systolic Right Ventricular Strain Measurement by Speckle-Tracking Echocardiography in Premature Infants

• Published in: Journal of the American Society of Echocardiography Vol. 26; no. 10; pp. 1201 - 1213
• Main Authors: Levy, Philip Thaler, MD, Holland, Mark R., PhD, Sekarski, Timothy J., RDCS, Hamvas, Aaron, MD, Singh, Gautam K., MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-10-2013
• Subjects: Cardiovascular; Echocardiography - methods; Feasibility Studies; Female; Global longitudinal strain; Heart Ventricles - diagnostic imaging; Humans; Image Processing, Computer-Assisted; Infant, Newborn; Infant, Premature; Male; Premature infants; Prognosis; Reproducibility of Results; Right ventricle; Speckle-tracking echocardiography; Systole - physiology; Systolic function; Premature infants; RV; STE; Two-dimensional; Global longitudinal strain; Coefficient of variation; Speckle-tracking echocardiography; 2D; Postmenstrual age; Region of interest; Peak global longitudinal strain; Limits of agreement; LOA; pGLSr; Intraclass correlation coefficient; Peak global longitudinal strain rate; PMA; Right ventricle; CI; ICC; pGLS; ROI; Confidence interval; CV; DTI; Right ventricular; Doppler tissue imaging; Systolic function
• ISSN: 0894-7317; 1097-6795
• DOI: 10.1016/j.echo.2013.06.005

Background Right ventricular (RV) systolic function is an important prognostic determinant of cardiopulmonary pathologies in premature infants. Measurements of dominant RV longitudinal deformation are likely to provide a sensitive measure of RV function. An approach for image acquisition and postacquisition processing is needed for reliable and reproducible measurements of myocardial deformation by two-dimensional (2D) speckle-tracking echocardiography. The aims of this study were to determine the feasibility and reproducibility of 2D speckle-tracking echocardiographic measurement of RV peak global longitudinal strain (pGLS) and peak global longitudinal strain rate in premature infants and to establish methods for acquiring and analyzing strain. Methods The study was designed in two phases: (1) a training phase to develop methods of image acquisition and postprocessing in a cohort of 30 premature infants (born at 28 ± 1 weeks) and (2) a study phase to prospectively test in a separate cohort of 50 premature infants (born at 27 ± 1 weeks) if the methods improved the feasibility and reproducibility of RV pGLS and peak global longitudinal strain rate measurements to a clinically significant level, assessed using Bland-Altman analysis (bias, limits of agreement, coefficient of variation, and intraclass correlation coefficient). Results Strain imaging was feasible from 84% of the acquisitions using the methods developed for optimal speckle brightness and frame rate for RV-focused image acquisition. There was high intraobserver (bias, 3%; 95% limits of agreement, −1.6 to +1.6; coefficient of variation, 2.7%; intraclass correlation coefficient, 0.97; P  = .02) and interobserver (bias, 7%; 95% limits of agreement, −4.8 to +4.73; coefficient of variation, 3.9%; intraclass correlation coefficient, 0.93; P < .05) reproducibility, with excellent linear correlation between the two pGLS measurements ( r  = 0.97 [ P < .01] and r  = 0.93 [ P < .05], respectively). Conclusions This study demonstrates high clinical feasibility and reproducibility of RV pGLS and RV peak global longitudinal strain rate measurements by 2D speckle-tracking echocardiography in premature infants and offers methods for image acquisition and data analysis for systolic strain imaging that can provide a reliable assessment of global RV function.